The first woman to die from a rare heart condition after getting a Pfizer vaccination passed away a month ago.
Vaccinologist Helen Petousis-Harris today confirmed the woman suffered from a potentially fatal side-effect of the vaccine that causes the heart muscle wall to become inflamed and died in July.
The Covid-19 Vaccine Independent Safety Monitoring Board today called for clinicians and the public to remain vigilant and aware of the signs of myocarditis and pericarditis following the fatality.
While the woman's death was still under investigation the safety monitoring board said it considered it was due to myocarditis, a known rare side effect of the Pfizer vaccine.
Myocarditis is an inflammation of the heart muscle wall which is often caused by a viral infection.
Every year more than 100 New Zealanders are discharged from hospital diagnosed with myocarditis.
Describing the death as "really unfortunate" Petousis-Harris today said it was extremely rare someone would lose their life after contracting myocarditis as a result of the Pfizer vaccination, with most needing a short stint in hospital before making a full recovery.
"In most of these cases, someone will go to hospital for a few days but deaths from myocarditis are really rare" she said.
She said the benefits of using the Pfizer vaccination continued to outweigh the risk of getting Covid or the inoculation's side effects.
"There's no vaccine or medicine that is without some side effects and these are just incredibly rare. Fortunately most people recover well," she said.
While the woman's death was the first in New Zealand so far five people in the European Union had died from the condition after 160 million vaccine doses.
She said myocarditis was normally quite a mild side effect with an average of a two-day stay in hospital and resolving without a lot of treatment.
"So in most cases it's quite mild."
She said the risk of myocarditis depended on age and gender but if you were female over 30 you're talking one or two cases per million people.
The highest risk group were males under 30 where it was more like 20-30 cases per million.
In comparison the risks from the disease were considerably higher, she said.
Petousis-Harris said the potential risk from the Pfizer vaccination was picked up a few months ago.
Associate Professor James Ussher, a microbiologist at the University of Otago, called it a "dreadfully sad and unfortunate case" but said the benefits "far outweigh the risks".
"To date, the vast majority of cases of myocarditis following vaccination with the Pfizer or Moderna vaccines have been mild, with resolution of both symptoms and inflammation with anti-inflammatories."
An Israeli study has found myocarditis occurred in 2.7 per 100,000 persons vaccinated with the Pfizer vaccine. The same study found that the risk of myocarditis with Covid-19 was four times higher (11.0 per 100,000 persons infected).